Portable tank apparatus and method of use

ABSTRACT

A tank assembly comprises a plurality of tank sections. Each tank section is capable of being connected to at least one other tank section. Each tank section is dimensioned to enable the section to be accommodated at or within a predetermined width limit for transportation by public road. A dimension of the tank directed across the sections when the tank is assembled exceeds the predetermined width limit.

This application is a divisional of U.S. application Ser. No. 11/052,683filed Feb. 7, 2005, and claims the benefit thereof.

FIELD OF THE INVENTION

This invention relates to portable tanks, in particular, tankstransportable by trailer.

BACKGROUND OF THE INVENTION

A clarifier/thickener tank of a clarifier/thickener system serves twopurposes. First, the clarifying aspect of the tank produces liquidclarified of suspended solids. Secondly, the thickener aspect of thetank concentrates the clarified suspended solids to an increased solidspercentage.

Most conventional clarifier/thickener tanks have a cylindrical shape. Arectangular shape is sometimes used but is less common because ofinefficiencies that can be introduced during clarification from thisgeometry. The cylindrical form is the most common configuration andefficient in terms of clarifier ability. The performance of thethickener aspect is independent of shape but dependent on the overalldepth of the tank which provides weight from the fluid itself and theoverlying thickened sludge to dewater or thicken the slurry. Aclarifier/thickener tank typically has a funnel shaped bottom with steepsides to assist in removal of the solid slurry. For a conventionalclarifier/thickener tank equipped with a sludge removal device such as arake system, the slope of the bottom is about 1.5 inches for everytwelve inches of run. The preferred diameter of a cylindricalclarifier/thickener tank can vary depending on the water flow rate, thedensity of the slurry, the slurry setting characteristics and otherfactors.

It is desirable to have a portable clarifier/thickener system so thatthe system may be transported to locations where the temporary use ofthe system is desired without the effort and expense of constructing anddismantling a fixed installation at each location the system isutilized. These construction and dismantling activities involveconsiderable expense from the labor, transportation and crane rentalrequired to complete the installation. These costs become even moresignificant if the locale of operation is in a remote area or access tothe site is intermittent.

The diameter of tanks which can be transported is limited bytransportation laws which limit the width of a load which can betransported by road. As transported loads increase beyond a width of 10to 12 feet, increasingly expensive and restrictive permits requirepurchase. For example, as load widths increase beyond 14 feet it iscommon for the permits to require the use of escort vehicles as well aslimitations on the routes and times that the load can be transported.(See, for example, Nova Scotia Department of Transportation & PublicWorks, Highway Operations, Policies and Procedures Manual, ProcedureNumber PR5033, Mar. 5, 2006.) As a result, the transport limitationsplace a limit on the clarifying rate of such a system since theclarifying rate of a clarifier/thickener tank is dependent on the squarefoot surface area of the interior of the tank. To overcome thislimitation, multiple smaller tanks can be placed in series. However,this creates complexity in the system from duplication of piping,valves, sludge pumps, feed splitters, etc. Also, the capacity toaccumulate and thicken solids depends on the volume of the tank.

SUMMARY OF THE INVENTION

A portable tank is disclosed which allows for rapid and inexpensivemobilization and demobilization of a clarifier/thickener at multiplelocations while maintaining a desirable clarification.

According to one broad aspect, the invention provides a tank assemblycomprising a plurality of tank sections each capable of being connectedto at least one other tank section, wherein each tank section has adimension that enables the section to be accommodated at or within apredetermined width limit for transportation by public road, and whereina dimension of the tank directly across the sections when the tank isassembled exceeds said predetermined width limit.

In some embodiments, the tank assembly comprises a bottom and a sidewall extending upwardly from said bottom and wherein at least twosections each comprise a portion of said bottom and a portion of saidside wall.

In some embodiments, said predetermined width limit is defined as themaximum width for transportation without a permit in the jurisdiction inwhich said tank is to be transported.

In some embodiments, said dimension of the tank directed across thesections is 11 feet or more.

In some embodiments, each section has opposed edges in which one of saidedges is for connection to another tank section and a dimension betweensaid edges is greater than half said predetermined width limit.

In some embodiments, the tank assembly further comprises mounting meansfor mounting a fluid treatment device therein.

In some embodiments, said tank comprises mounting means for mounting arotary device therein.

In some embodiments, said rotary device includes a rotor having adiameter which exceeds said predetermined width limit.

In some embodiments, said tank when assembled is substantiallycylindrical.

In some embodiments, the plurality of tank sections comprise twosubstantially uniform semi-cylindrical halves.

In some embodiments, the opposed edges define an open face in atransportation position.

In some embodiments, the at least two tank sections are pivotallyattached along the divide.

In some embodiments, at least two tank sections are pivotally attached.

In some embodiments, the tank assembly further comprises at least aportion of at least one of a clarifier and a thickener mounted to saidtank assembly.

In some embodiments the tank sections are adapted to together holdliquid when the tank is assembled.

In some embodiments, the tank assembly further comprises a frame andwheels supporting the tank sections.

In some embodiments, the tank assembly further comprises a plurality ofretractable downward supports for supporting the assembled tank.

According to one broad aspect the invention provides a tank assemblycomprising a plurality of tank sections each capable of being connectedto at least one other tank section and a fluid treatment apparatuscapable of being mounted within the tank assembly when the tank assemblyis assembled.

In some embodiments, the fluid treatment apparatus comprises at leastone of a clarifier and a thickener.

In some embodiments, said tank assembly has an upper portion and a lowerportion and the divide between at least two tank sections is directedfrom said upper portion to said lower portion of said tank.

In some embodiments, the at least two tank sections are pivotallyattached along the divide.

In some embodiments, the tank assembly further comprises a first supportconnected to the first tank section at a position spaced from thepivotal axis, and extending upwardly therefrom and coupled to a secondsupport for supporting at least part of the weight of at least one ofthe tank sections.

According to one broad aspect, the invention provides a method oftransporting a tank assembly comprising providing at least two tanksections wherein each tank section has a dimension that enables thesection to be accommodated at or within a predetermined width limit fortransportation by public road and wherein a dimension of the tankassembly directed across the sections when the tank assembly isassembled exceeds said predetermined width limit and orienting each tanksection for transportation with the dimension that enables the sectionto be accommodated at or within a predetermined width limit directedacross the width of the road.

According to one broad aspect, the invention provides a method ofassembling a first tank section and a second tank section pivotallyconnected to each other by a pivotal connection, comprising providingsupport for supporting the first tank section, such that the second tanksection is free to move relative to said first tank section about saidpivotal axis, and rotating the second tank section about the pivotalconnection to form an assembled tank with the first tank section.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention will now be described withreference to the attached drawings in which:

FIG. 1 is left side view of a portable tank apparatus according to anembodiment of the invention;

FIG. 2 is a right side view of the embodiment of FIG. 1;

FIG. 3 is a top view of the embodiment of FIG. 1;

FIG. 4A is a perspective view of a pivoting hinge post assemblyaccording to the embodiment of FIG. 1;

FIG. 4B is a perspective view of a stationary hinge post assemblyaccording to the embodiment of FIG. 1;

FIG. 5 is a bottom perspective view of a pivot tank section according tothe embodiment of FIG. 1;

FIG. 6 is a bottom perspective view of a stationary tank sectionaccording to the embodiment of FIG. 1;

FIG. 7 is a perspective view of the embodiment of FIG. 1 with the pivottank section in a partially rotated position; and

FIG. 8 is a perspective view of the embodiment of FIG. 1 with the pivottank section in a closed position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a portable tank assembly 10 which includes a trailer deck16, a stationary tank section 14 and a pivot tank section 12. Supportingtrailer wheels 18 are provided on the trailer deck 16 and are locatedtowards the rear of the trailer deck 16. The stationary tank section 14rests on supports (not shown) on the trailer deck 16 towards the frontof the trailer deck 16 and the pivot tank section 12 rests on supports(not shown) on the trailer deck 16 towards the rear of the trailer deck16. The supports are constructed of hollow structural steel welded tothe trailer deck 16 and support each of tank sections 12 and 14 at threepoints on the respective tank sections 12 and 14. The supports for thestationary tank section 14 are permanently welded, while the supportsfor the pivot tank section 12 are bolted to allow the pivot tank section12 to pivot as required.

The pivot tank section 12 and the stationary tank section 14 aresemi-cylindrical tank halves with vertical side walls, a semi-conicalshaped bottom, an open face and an open top.

FIG. 1 shows an interior view of the tank sections 12 and 14. Verticalflanges 60 are provided on both tank sections 12 and 14. The verticalflanges 60 extend up the two vertical edges of the open face of each ofthe tank sections 12 and 14. The vertical flanges 60 extend outward fromthe vertical edges parallel to the open faces of the tank sections 12and 14 and form opposed edges extending between an upper portion and alower portion of the tank sections 12 and 14. The flanges 60 have aplurality of closely spaced bolt holes defined therethrough. Similarly,bottom flanges 62 are provided which extend outward from the edge of thesemi-conical shaped bottom of the open face of the tank sections 12 and14. The bottom flanges 62 extend parallel to the open faces of the tanksections 12 and 14. The flanges 60 and 62 define a divide between thetwo tank sections 12 and 14 when assembled. A plurality of bolt holesare also defined through the bottom flanges 62.

Both tank sections 12 and 14 include weir halfs 26. The weir halfs 26are continuous pieces of sheet metal with serrated upper edges. Each ofthe weir halfs 26 are welded to the tank sections 12 and 14. The weirhalfs 26 are positioned along an upper inner circumference of the wallof each of the tank sections 12 and 14. Each of the weir halfs 26 isangled inward from the respective wall of tank sections 12 and 14 at anapproximately 45 degree angle. The weir halfs 26 are welded to the wallsof tank sections 12 and 14 with a water-tight seal. The weir halfs 26include weir flanges 92 located at the vertical edges of the weir halfs26. The weir flanges 92 extend inward parallel to the open faces of thetank sections 12 and 14. The weir flanges 92 also have a plurality ofbolt holes defined therethrough.

Three stationary jack legs 20 are fixed to the bottom surface of thestationary tank section 14. The stationary jack legs 20 are spacedaround the circumference of the stationary tank section 14. Thestationary jack legs 20 overhang the edge of the trailer deck 16. Thestationary jack legs 20 are shown in retracted position in FIG. 1.

Three pivot jack legs 22 are affixed to a bottom surface of the pivottank section 12. The pivot jack legs 22 are spaced around thecircumference of the pivot tank section 12. The pivot jack legs 22 aredepicted in FIG. 1 in a retracted and folded position. In the foldedposition, the pivot jack legs 22 may rest on the trailer deck 16. Thejack legs 20 and 22 are shown in more detail in FIGS. 5 and 6. The jacklegs 20 and 22 provide retractable support for the tank sections 12 and14.

The stationary tank section 14 includes a stationary cross member 38.The stationary cross member 38 extends laterally across the stationarytank section 14 adjacent an upper end of the open face of the stationarytank section 14. Similarly, the pivot tank section 12 includes a pivotcross member 40. The pivot cross member 40 extends laterally across thepivot tank section 12 adjacent an upper end of the open face of thepivot tank section 12. Six hand rails 24 are attached to the crossmembers 38 and 40. The hand rails 24 are bolted to the innerlongitudinal sides of the cross members 38 and 40 opposite to the openface of the tank sections 12 and 14.

A drive assembly is supported by the cross member 38. The drive assemblyconsists of an electric motor 44, a gear reducer 46 and drive plate 48at an upper end. The electric motor is connected to the gear reducer 46which in turn is connected to the drive plate 48. The drive assemblyalso includes a drive pipe 52, a dispersion plate 54, a tube 42, aninput pipe 50 and a rake assembly 166. The drive plate 48 is connectedto the drive pipe 52 which extends down through a center of the tube 42.The dispersion plate 54 is connected to the tube 42 by four threadedrods (not shown). The rake assembly 166 is bolted to a lower end of thedrive pipe 52. The input pipe 50 is connected to an outside pipeconnection 51 by a flexible connection (not shown). The input pipe 50extends out from an upper side of the tube 42. The input pipe 50 ends ina flange for easy connection to outside connection pipe connection 51.The means by which the drive assembly is supported is described ingreater detail with respect to FIG. 3.

A bottom cone 56 is provided at a bottom point of the semi-conical shapebottom of the stationary tank section 14. Two output pipes 58 extend outfrom angled sides of the bottom cone 56. The output pipes 58 end withflanges for ready connection to associated piping and sludge pump (notshown).

The pivot tank section 12 is connected to the stationary tank section 14by a loose hinge assembly. The hinge assembly includes hinge posts 30and 32 and pairs of hinge plates 34 and 36. The pivot hinge post 32 isvertically oriented and bolted to the pivot tank section 12 by thefrontward vertical flange 60 of the pivot tank section 12. The pivothinge plates 34 are bolted to the pivot hinge post 32. The stationaryhinge post 30 is vertically oriented and bolted to the stationary tanksection 14 by the rearward vertical flange 60 of the stationary tanksection 14. The stationary hinge plates 36 are bolted to the stationaryhinge post 30. Each of the pairs of hinge plates 34 and 36 are bolted toopposite ends of the hinge posts 30 and 32. The hinge assembly isdescribed in greater detail with reference to FIGS. 4A and 4B.

A mast assembly extends upward from the stationary hinge post 30. Themast assembly includes a mast 28, a cable 162, a mast support 160 and amast arm 164. The mast 28 is a steel tube. The mast 28 has associatedwith it a mast upper top plate 170, a mast lower top plate 172, a plateangle support 174, an upper mast pivot 176 and a lower mast pivot 178.

The mast upper top plate 170 and the mast lower top plate 172 each havea protrusion with a hole defined therethrough. The mast upper top plate170 and the mast lower top plate 172 are fastened at the top of the mast28 with the mast lower top plate 172 spaced below the mast upper topplate 170. The holes in their protrusions are vertically aligned. Theplate angle support 174 is a triangle plate welded between the mast 28and the bottom of the protrusion of the mast lower top plate 172 forsupport.

The upper mast pivot 176 are cylindrical with an attachment flangeextending from one side. A pin extends through the hole in theprotrusion in the upper top plate 170 through the center of the uppermast pivot 176 and through the hole in the protrusion in the lower topplate 172.

The mast support 160 is a steel rod. The mast support 160 is angledbetween a rearward brace leg 82 (see FIG. 6) and an upper point of themast 28. The mast support 160 is removably bolted at each end.

The mast arm 164 is a steel rod. The mast arm 164 is horizontal and isconnected at one end to an intermediate point of a brace 74 (see FIG. 3)and at the other end to the lower mast pivot 178. The mast cable 162connects the upper mast pivot 176 to the end of the mast arm 164 whichconnects to the brace 74 (see FIGS. 7 and 8).

The bottom end of the mast 28 is bolted to the top of a mast bearingsupport end flange 128 (see FIG. 4B).

FIG. 2 shows a rear view of the tank sections 12 and 14. The tanksections 12 and 14 include vertical stiffeners 72. The verticalstiffeners 72 are comprised of elongated flat pieces of metal. Thevertical stiffeners 72 are welded to an outer surface of the walls ofthe tank sections 12 and 14 such that they extend vertically. The tanksections 12 and 14 also includes similar horizontally orientedstiffeners (not shown) on the bottom.

The stationary tank section 14 includes a discharge box 68 which islocated adjacent the top rear of the stationary tank section 14. Thedischarge box 68 is hollow and open topped with a substantiallytriangular cross-section and a discharge pipe 70 extending from itsbottom surface. The discharge pipe 70 ends in a flange for attachment toother piping of the assembly (not shown). The discharge box 68communicates with the interior of the stationary tank section 14 througha hole in the wall of the stationary tank section 14 (not shown). Thehole through the wall of stationary tank section 14 is defined above theweir half 26 of the stationary tank section 14. The discharge box 68 iswelded to the rear surface of the stationary tank section 14 in a fluidtight manner.

FIG. 3 shows the position of the tank sections 12 and 14 on the trailerdeck 16. In particular, the tanks sections 12 and 14 take upsubstantially the entire length of the trailer 16 and slightly overhangthe edges of the trailer 16. The weir halfs 26 extending around thecircumference of the tanks sections 12 and 14 can be clearly seen inFIG. 3. The substantially triangular cross-sectional shape of dischargebox 68 can also be clearly seen in FIG. 3.

FIG. 3 shows the support structure for the drive assembly. Inparticular, the pivot tank section 12 has drive supports 76 and anglebraces 78. The drive supports 76 extend laterally from the bottomsurface of the cross member 40 symmetrically spaced around a midpoint ofthe cross member 40. The drive supports 76 extend toward the open faceof the pivot tank section 12. The angle braces 78 extend at anapproximate 45 degree angle between the cross member 40 and an outer endof the drive supports 76. The drive supports 76 are spaced to fit underthe drive plate 48. The drive assembly is shown in its transportationposition such that it is not centered on the center line of the tank. Inthis position, the drive assembly is supported by the drive supports 88of stationary tank section 14 alone. In operation mode the drive plate48 is unbolted from the drive supports 88 and shifted and bolted on boththe drive supports 88 and the drive supports 76 present on both tanksections 12 and 14 and centered along the centerline of the assembledtank.

The cross member 40 also includes brace legs 84. The brace legs 84extend laterally from the open face side of the cross member 40 andterminate in flanges at the open face of the pivot tank section 12. Thebrace 74 is provided in the pivot tank section 12. The brace 74 extendshorizontally between a centre point of the cross member 40 and the outersurface of the tank. The brace 74 is a beam which helps preventdeformation of the pivot tank section 12 during rotation.

The stationary tank section 14 also include drive supports 88 (see FIG.6) and angle braces 86 which provide support for the drive assembly. Thedrive supports 88 extend outwardly from the cross member 38 under thedrive plate 48. The angle braces 86 extend at an approximately 45 degreeangle between the cross member 38 and ends of the drive supports 88.

The cross member 38 also includes brace legs 82. The brace legs 82 arespaced along the cross brace 38 and extend outwardly therefrom. Thebrace legs 82 terminate in flanges at the open face of the stationarytank section 14. The brace legs 82 are positioned to mate with legbraces 84 when the tank is in a closed position.

Also visible in FIG. 3 are cone bottom flanges 80 of the tank sections12 and 14 which have a plurality of bolt holes defined therethrough.Cone bottom flanges are horizontal and connect the bottom cone 56 to thetank sections 12 and 14 when assembled.

FIGS. 4A and 4B show details of the hinge posts 30 and 32 and the hingeplates 34 and 36. Turning to FIG. 4A, FIG. 4A shows the pivot hinge post32. The pivot hinge post 32 is an elongated hollow steel post with asquare cross section. Also depicted are two hinge base plates 104. Eachof the hinge base plates 104 is a flat rectangular plate with six boltholes defined around the perimeter. A first hinge base plate 104 iswelded at an upper end of the pivot hinge post 32 and a second hingebase plate 104 is welded at the bottom end of the pivot hinge post 32.Defined in the opposite face of the pivot hinge post 32 from the hingebase plates 104 is an upper rim opening 100 and a lower rim opening 102.The upper rim opening 100 is located adjacent the top of the pivot hingepost 32 and accommodates a top side rim 98 (FIG. 5) of the pivot tanksection 12 when the pivot hinge post 32 is bolted to the pivot tanksection 12. Similarly, the lower rim opening 102 accommodates a bottomside rim 96 (FIG. 5) of the pivot tank section 12 when the pivot hingepost 32 is bolted to the pivot tank section 12.

Two rotating hinge support plates 110 extend outwardly from the pivothinge plate 34. The rotating hinge support plates 110 are perpendicularto the pivot hinge plate 34. A rotating hinge 106 extends through and isconnected to the outer end of each rotating hinge support plate 110. Apivot hinge web plate 108 is provided which extends between the tworotating hinge support plates 110. Also provided are two pivot hingegussets 112 which connect from the rotating hinge support plate 110 tothe pivot hinge plate 34. The pivot hinge web plate 108 and the pivothinge gussets 112 further support the hinge assembly. The entire hingeassembly structure may be welded together or may be cast as a singlepart. The pivot hinge plate 34 has six bolt holes defined therethroughwhich match to the bolt holes in the hinge base plate 104 to allow eachpivot hinge plate 34 to be bolted to one of the hinge base plate 104.

Turning to FIG. 4B, FIG. 4B shows the stationary hinge post 30 which isalso an elongated steel hollow post having a square cross section. Aseries of bolt holes 190 are defined up a side face of the stationaryhinge post 30 to enable bolting of the stationary hinge post 30 to therearward vertical flange 60 of the stationary tank section 14. A lowerrim opening 124 is defined adjacent a lower end of one face of thestationary hinge post 30. The lower rim opening 124 is shaped toaccommodate the bottom side rim 196 (see FIG. 6) of the stationary tanksection 14. Similarly, adjacent an upper end of the stationary hingepost 30, there is defined an upper rim opening 122 which is sized toaccommodate the top side rim 198 (see FIG. 6) of the stationary tanksection 14 such that the stationary hinge post 30 can be bolted flushagainst the exterior side of the stationary tank section 14.

The stationary hinge assembly includes hinge base plates 120 andstationary hinge plates 36. The hinge base plates 120 are located on anopposite face of the stationary hinge post 30 from the openings 122 and124. There are two hinge base plates 120, one adjacent the lower end ofthe stationary hinge post 30 and the other adjacent the upper end of thestationary hinge post 30. The flat steel hinge base plates 120 have fourholes spaced along each of their vertical edges to accommodateattachment of the stationary hinge plates 36.

The stationary hinge plates 36 have four holes defined on each of thevertical edges which align with the holes of the hinge base plates 120to allow bolting together of the stationary hinge plate 36 and the hingebase plates 120. Three stationary hinge support plates 118 extendinglaterally outwardly from the hinge base plates 36. A stationary hinge114 is located at an outer end of each of the stationary support plates118. The stationary hinges 114 are cylindrical and in vertical alignmentbut spaced apart to accommodate the rotating hinges 106 of the pivothinge plate 34 when assembled. Two stationary hinge web plates 116connect pairs of the stationary hinge support plates 118. The hingeassembly can be cast as a single part or have component parts weldedtogether.

The mast bearing support end flange 128 and a mast bearing support 126are also provided. The mast bearing support end flange 128 issubstantially a square flat plate with protrusion extending from onecorner. There are bolt holes defined through the four corners of thesquare portion to allow bolting of the mast 28 to the mast bearingsupport end flange 128. There is also a hole defined through the outerend of the protrusion. The mast bearing support 126 has the same shapeas the protrusion of the mast bearing support end flange 128. A mastbearing support end flange 128 is positioned atop the stationary hingepost 30. The mast bearing support 126 is positioned directly in avertical alignment below the mast bearing support end flange 128 andabove the upper stationary hinge plate 36. The mast bearing support 126also has a hole defined through it at an extent which is in alignmentwith the hole defined through the end of the protrusion of the mastbearing support end flange 128. The mast bearing support 126 and theprotrusion of the mast bearing support end flange 128 extend outwardlylaterally from a corner from the stationary hinge support 30 over thestationary hinge plates 36. A cylindrical lower mast pivot 178 (seeFIG. 1) is provided with an attachment flange extending from one side.The mast bearing support 126 and the mast bearing support end flange 128support an end of the mast arm 164 (see FIG. 1) through the lower mastpivot 178.

FIG. 5 shows bottom details of the pivot tank section 12. In particular,the connection of the brace legs 84, the drive supports 76, and theangle braces 78 to the cross member 40 can be more clearly seen. Thedrive supports 76 and the angle braces 78 extend along a bottom of thecross member 40 and are fastened thereto by welding or bolting.

The pivot jack legs 22 can also be seen in more detail in FIG. 5. Inparticular, the pivot jack legs 22 each comprise a pivot leg bottom 140a pivot leg top 144, a jack connection 142, and a leg post 150. Thepivot leg bottoms 140 and the pivot leg tops 144 are connected by thejack connections 142. A leg support plate 146 is provided at the top ofeach pivot leg top 144. Each leg support plate 146 is a flat squareplate which is perpendicular to the direction of the leg 22 andoverhangs the sides of the pivot leg top 144. Defined in each of thefour corners of the leg support plates 146 are bolt holes.

FIG. 5 also shows leg base plates 148 which are flat square plates withbolt holes defined in the four corners which mirror the bolt holes ofthe leg support plates 146. The leg base plates 148 are located at thelower end of the leg posts 150 which are permanently fixed to the bottomof the pivot tank section 12. The leg base plates 148 and the legsupport plates 146 are hinged along one edge (see FIG. 1). In FIG. 1,the legs 22 are shown in a folded position. In FIG. 5, the legs 22 areshown in their use position in which legs 22 are rotated about the hingebetween the leg support plates 146 and the leg base plates 148 to bebrought into the vertical position. The leg 22 is then retained in thisposition by bolting together the leg support plates 146 and the leg baseplates 148.

FIG. 6 shows the bottom details of the stationary tank section 14. Aswith FIG. 5, FIG. 6 shows how the drive supports 88, the angle braces 86and the brace legs 82 are connected to the cross brace 38. Inparticular, the drive supports 88 and the angle braces 86 extend acrossa bottom surface of the cross member 38 and are bolted or weldedthereto.

FIG. 6 also shows the stationary jack legs 20. The stationary jack legs20 are comprised of stationary leg tops 156, stationary leg bottoms 154and jack connectors 152. The stationary leg tops 156 and the stationaryleg bottoms 154 are square steel legs. The stationary leg top 156 andthe stationary leg bottom 154 are connected by the jack connection 152.The stationary leg tops 156 terminate at their upper ends with leg baseplates 158. Each leg base plate 158 has bolt holes defined through eachof its four corners for attachment to the bottom of the stationary tanksection 14.

The portable tank assembly 10 is transported in the position depicted inFIGS. 1, 2 and 3 with the exception that the mast 28 is normally loweredfor transportation. In particular, the mast support 160, the mast 28 andthe mast cable 162 are removed for transportation. The hand rails 24,bottom cone 56 and one rake arm of the rake assembly 166 that extendsbeyond the footprint of the trailer deck 16 are removed. FIG. 7 showsthe one arm that needs to be removed during transport.

The trailer deck 16 is connected to a transport truck and towed to thelocation where the portable assembly 10 is to be used. In thisconfiguration, the width of the assembly tank sections 12 and 14 acrossthe width of the road is within a predetermined width limit fortransportation without a permit or for transportation using the desiredpermit level (i.e. acceptable cost and restrictions). Once at thelocation for use, the pivot tank section 12 is prepared to be rotated toalign with the stationary tank section as shown in FIGS. 7 and 8. Themast 28 is positioned vertically and bolted to the top of the mastbearing support end flange 128. The mast cable 162 is attached from theupper mast pivot 176 at the top of the mast 28 to an outside corner ofthe mast arm 164. The mast assembly provides support to the pivot tanksection 12 during rotation. The bottom cone 56 is attached to thestationary tank section 14 and the rake arm that extends beyond thetrailer footprint is attached (FIG. 7). A gasket (not shown) is placedbetween the flanges 60, 62 and 92 of the two tank sections 12 and 14 andbetween the bottom cone 56 and the flanges 80 of the two tank sections12 and 14. The pivot tank section 12 rotates about the hinges 106 and114, which in use, have a pin extending therethrough to connect thehinges 106 and 114. The pivot tank 12 is rotated through the positionshown in FIG. 7 to the position shown in FIG. 8. At this point, boltsare inserted in all of the bolt holes in the flanges 60, 62, 92 and 80to fasten the two tank halves together in a liquid tight manner to holdliquid. Flanges at the ends of the brace legs 82 and 84 are fastened.The stationary jack legs 22 are jacked down to provide support. Thepivot jack legs 20 are also positioned to provide support by firstunfolding the jack legs to the vertical position and bolting the legsupports 146 to the leg base plates 148 (see FIG. 5). The pivot legbottoms 140 are then jacked down to provide support for the pivot tanksection 12. Next, the hand rails are installed and a fiberglass walkway(not shown) is positioned between the hand rails 24 and rests on thecross members 38 and 40 to provide access for an operator to walk to thedrive assembly. The motor, gear reducer, tube and drive pipe and driveplate assembly is shifted to operation mode.

Connections are then made to the various pipes to allow operation of aclarifier/thickener system utilizing the portable tank assembly 10. Inparticular, a pipe is connected to input pipe 50 to pump the fluid to betreated into the assembled portable tank assembly 10. In operation, thedispersion plate 54 acts to evenly spread the incoming slurry across thebottom of the assembled tank. The slurry enters in through the inputpipe 50 flows down through the tube 42 and is evenly spread through thecircumference of the tank by the dispersion plate 54. The threaded rodsallow the adjustment of the gap between the dispersion plate 54 and thetube 42 to allow for different flow rates. The connection of the drivepipe 52 to the rake assembly 166 connects the rake assembly 166 to thegear reducer 46 and motor 44. The rake moves at a rate around 3 rpm atthe rake tips and functions to “pull” the thickened sludge to the centerof the tank at the point of the bottom cone so that it can becontinuously pumped from the tank. The drive unit is actuated to drivethe drive assembly. The rake assembly 166 rakes in a circular motionaround the bottom of the tank for sludge treatment. Slurry is drainedout of the bottom of the tank through bottom output pipes 58. Clarifiedwater spills over the weir 26 and exits the tank through the dischargebox 68. The operation of the clarifier/thickener system is conducted ina manner known in the art.

In the operation configuration, the width of the assembly tank sections12 and 14 across the width of the road exceeds the predetermined widthlimit.

Although a specific embodiment of the invention has been explained, itwill be evident to those skilled in the art that modifications can bemade within the scope of the invention. For example, forms of legs otherthan jack legs and folding legs can be used. The legs couldalternatively be transported separately and installed at the worksite.Hydraulic legs may also be used.

With respect to the hinge, any sufficiently durable pivot means known inthe art could be used. With respect to pivoting the tank section 12 intoposition, means other than the mast assembly shown could be used tosupport the pivot tank section 12. For example, pivot section 12 couldbe supported manually from the bottom.

Other drive systems with or without rake systems could be used for theclarifier/thickener system. Additionally, this tank can be used in otherapplications, including other fluid treatment applications, andapparatuses outside of the field of clarifier/thickener systems. Otherrotary devices may also be used. The tank may be used for a clarifier orthickener system alone, rather than for both.

The portable tank assembly is preferably all steel construction butother materials of acceptable strength and durability can besubstituted. Welding and bolting of the steel section has beendescribed. Other attachment means can, of course, be alternatively use.

Although the invention is disclosed as having two equal semi-cylindricalsections, it will be understood other tank shapes and unequal divisionof the tank into two or more sections is contemplated by the invention.

1-26. (canceled)
 27. A tank assembly comprising: a plurality of tanksections; a frame and wheels supporting the tank sections; each tanksection capable of being connected to at least one other tank section,wherein each tank section has a dimension that enables the section to beaccommodated at or within a predetermined width limit for transportationby public road, and wherein, when the tank is assembled, a dimension ofthe tank directed across a transportation direction of the sections anda dimension of the tank directed along the transportation direction ofthe sections both exceed the predetermined width limit; and a fluidtreatment apparatus capable of being mounted within the tank assemblywhen the tank assembly is assembled.
 28. The tank assembly as claimed inclaim 27, further comprising a plurality of retractable downwardsupports for supporting the assembled tank.
 29. A tank assemblycomprising a plurality of tank sections each capable of being connectedto at least one other tank section and a fluid treatment apparatuscapable of being mounted within the tank assembly when the tank assemblyis assembled.
 30. The tank assembly as claimed in claim 29, wherein saidtank when assembled is substantially cylindrical.
 31. The tank assemblyas claimed in claim 29, wherein the plurality of tank sections comprisetwo substantially uniform semi-cylindrical halves.
 32. The tank assemblyas claimed in claim 29, wherein said dimension of the tank directedacross the sections is 11 feet or more.
 33. The tank assembly as claimedin claim 29, further comprising mounting means for mounting the fluidtreatment apparatus therein.
 34. The tank assembly as claimed in claim29, wherein the fluid treatment apparatus comprises at least one of aclarifier and a thickener.
 35. The tank assembly as claimed in claim 29,wherein said tank assembly has an upper portion and a lower portion andthe divide between at least two tank sections is directed from saidupper portion to said lower portion of said tank.
 36. The tank assemblyas claimed in claim 35, wherein the at least two tank sections arepivotally attached along the divide.
 37. The tank assembly as claimed inclaim 36, further comprising a first support connected to the first tanksection at a position spaced from the pivotal axis, and extendingupwardly therefrom and coupled to a second support for supporting atleast part of the weight of at least one of the tank sections.
 38. Amethod of transporting a tank assembly comprising: providing at leasttwo tank sections, a frame and wheels supporting the tank sections, anda fluid treatment apparatus capable of being mounted within the tankassembly when the tank assembly is assembled, wherein each tank sectionhas a dimension that enables the section to be accommodated at or withina predetermined width limit for transportation by public road andwherein, when the tank assembly is assembled, a dimension of the tankassembly directed across a transportation direction of the sections anda dimension of the tank assembly directed along the transportationdirection both exceed said predetermined width limit; and orienting eachtank section for transportation with the dimension that enables thesection to be accommodated at or within a predetermined width limitdirected across the width of the road.
 39. A method of assembling a tankassembly comprising a first tank section and a second tank sectionpivotally connected to each other by a pivotal connection, comprising:providing support for supporting the first tank section, such that thesecond tank section is free to move relative to said first tank sectionabout said pivotal axis; and rotating the second tank section about thepivotal connection to form an assembled tank with the first tanksection; mounting a fluid treatment apparatus within the tank assemblywhen the tank assembly is assembled.